The KVM/ARM MMU code doesn't take care of invalidating TLBs before
freeing a {pte,pmd} table. This could cause problems if the page
is reallocated and then speculated into by another CPU.
Reported-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/kvm/interrupts.S | 2 ++
arch/arm/kvm/mmu.c | 42 +++++++++++++++++++++++++++---------------
2 files changed, 29 insertions(+), 15 deletions(-)
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index f7793df..9e2d906c 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -37,6 +37,8 @@ __kvm_hyp_code_start:
*
* void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
*
+ * Invalidate TLB for the given IPA, or invalidate all if ipa is zero.
+ *
* We rely on the hardware to broadcast the TLB invalidation to all CPUs
* inside the inner-shareable domain (which is the case for all v7
* implementations). If we come across a non-IS SMP implementation, we'll
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 9657065..4a838db 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -43,7 +43,14 @@ static phys_addr_t hyp_idmap_vector;
static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
- kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
+ /*
+ * This function also gets called when dealing with HYP page
+ * tables. As HYP doesn't have an associated struct kvm (and
+ * the HYP page tables are fairly static), we don't do
+ * anything there.
+ */
+ if (kvm)
+ kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
}
static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
@@ -78,18 +85,20 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
return p;
}
-static void clear_pud_entry(pud_t *pud)
+static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
{
pmd_t *pmd_table = pmd_offset(pud, 0);
pud_clear(pud);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
pmd_free(NULL, pmd_table);
put_page(virt_to_page(pud));
}
-static void clear_pmd_entry(pmd_t *pmd)
+static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
{
pte_t *pte_table = pte_offset_kernel(pmd, 0);
pmd_clear(pmd);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
pte_free_kernel(NULL, pte_table);
put_page(virt_to_page(pmd));
}
@@ -100,11 +109,12 @@ static bool pmd_empty(pmd_t *pmd)
return page_count(pmd_page) == 1;
}
-static void clear_pte_entry(pte_t *pte)
+static void clear_pte_entry(struct kvm *kvm, pte_t *pte, phys_addr_t addr)
{
if (pte_present(*pte)) {
kvm_set_pte(pte, __pte(0));
put_page(virt_to_page(pte));
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
}
}
@@ -114,7 +124,8 @@ static bool pte_empty(pte_t *pte)
return page_count(pte_page) == 1;
}
-static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size)
+static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
+ unsigned long long start, u64 size)
{
pgd_t *pgd;
pud_t *pud;
@@ -138,15 +149,15 @@ static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size)
}
pte = pte_offset_kernel(pmd, addr);
- clear_pte_entry(pte);
+ clear_pte_entry(kvm, pte, addr);
range = PAGE_SIZE;
/* If we emptied the pte, walk back up the ladder */
if (pte_empty(pte)) {
- clear_pmd_entry(pmd);
+ clear_pmd_entry(kvm, pmd, addr);
range = PMD_SIZE;
if (pmd_empty(pmd)) {
- clear_pud_entry(pud);
+ clear_pud_entry(kvm, pud, addr);
range = PUD_SIZE;
}
}
@@ -165,14 +176,14 @@ void free_boot_hyp_pgd(void)
mutex_lock(&kvm_hyp_pgd_mutex);
if (boot_hyp_pgd) {
- unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
- unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
+ unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
+ unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
kfree(boot_hyp_pgd);
boot_hyp_pgd = NULL;
}
if (hyp_pgd)
- unmap_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
+ unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
kfree(init_bounce_page);
init_bounce_page = NULL;
@@ -200,9 +211,10 @@ void free_hyp_pgds(void)
if (hyp_pgd) {
for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
- unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
+ unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
- unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
+ unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
+
kfree(hyp_pgd);
hyp_pgd = NULL;
}
@@ -393,7 +405,7 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm)
*/
static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
{
- unmap_range(kvm->arch.pgd, start, size);
+ unmap_range(kvm, kvm->arch.pgd, start, size);
}
/**
@@ -413,6 +425,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
return;
unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
+ kvm_tlb_flush_vmid_ipa(kvm, 0); /* Invalidate TLB ALL */
free_pages((unsigned long)kvm->arch.pgd, S2_PGD_ORDER);
kvm->arch.pgd = NULL;
}
@@ -675,7 +688,6 @@ static void handle_hva_to_gpa(struct kvm *kvm,
static void kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
{
unmap_stage2_range(kvm, gpa, PAGE_SIZE);
- kvm_tlb_flush_vmid_ipa(kvm, gpa);
}
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
--
1.8.2.1
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